refactor(PdfPreview): 优化代码格式并添加加载状态

- 调整模板中的 `van-popup` 属性换行，提高代码可读性
- 添加 `loading` 状态变量，用于管理 PDF 加载状态
- 统一 CSS 样式缩进，保持代码风格一致

@@ -3,7 +3,8 @@
  * @Description: PDF预览组件
 -->
 <template>
-    <van-popup v-if="show" :show="show" @update:show="emit('update:show', $event)" position="right" :style="{ height: '100%', width: '100%' }">
+    <van-popup v-if="show" :show="show" @update:show="emit('update:show', $event)" position="right"
+        :style="{ height: '100%', width: '100%' }">
         <div id="pdf-container"></div>
         <van-button class="close-btn" type="default" icon="cross" round @click="emit('update:show', false)" />
     </van-popup>
@@ -32,6 +33,7 @@ const props = defineProps({
 const emit = defineEmits(['update:show']);
 
 // PDF Worker路径
+const loading = ref(false);
 const pdfPath = new URL("@sunsetglow/vue-pdf-viewer/dist/libs/pdf.worker.min.js", import.meta.url).href;
 
 // 监听show属性变化
@@ -49,9 +51,7 @@ const initPdfViewer = () => {
             loadFileUrl: props.url,
             pdfPath: pdfPath,
             loading: (load, fileInfo) => {
-                if (!load) {
-                    // configPdfApiOptions.onSearch("", false);
-                }
+                loading.value = load;
             },
             pdfOption: {
                 search: false,
@@ -76,21 +76,21 @@ const initPdfViewer = () => {
 
 <style scoped>
 #pdf-container {
-  width: 100%;
-  padding: 0px;
-  height: 100%;
+    width: 100%;
+    padding: 0px;
+    height: 100%;
 }
 
 .close-btn {
-  position: fixed;
-  right: 20px;
-  bottom: 20px;
-  z-index: 100;
-  width: 40px;
-  height: 40px;
-  padding: 0;
-  border-radius: 50%;
-  background: rgba(0, 0, 0, 0.6);
-  color: #fff;
+    position: fixed;
+    right: 20px;
+    bottom: 20px;
+    z-index: 100;
+    width: 40px;
+    height: 40px;
+    padding: 0;
+    border-radius: 50%;
+    background: rgba(0, 0, 0, 0.6);
+    color: #fff;
 }
 </style>